Laser diodes are semiconductor devices which emit a beam of substantially coherent light. Such devices, in general, comprise a body of a semiconductor material having therein a semiconductor p-n junction and a waveguide region adjacent the junction. When a suitable voltage is placed across the body, opposite charge carriers are generated across the junction which recombine in the waveguide to create light. Spaced reflectors are provided along the waveguide to create a cavity along which the light is reflected back and forth to form a substantially coherent beam. Generally, the light beam is emitted from one or both ends of the waveguide. However, laser diodes have been designed in which the light beam is emitted from a surface of the waveguide.
Laser diodes are used as a source of light in various applications, such as optical communication systems, computers and printers. For some of these applications, it is desirable to have a light emitting device which emits a plurality of closely spaced light beams. For this purpose, arrays of a plurality of the laser diodes have been built in a single body of semiconductor material. However, a problem in building such an array is to be able to have the emitted beams close together while providing the necessary electrical and thermal isolation between adjacent laser diodes in the array. Also, for some applications, it is desirable to have an array which emits a plurality of beams of different wavelengths.